Fighting outside the control zone?

I played about 7 hours over the weekend. Overall I enjoyed it.

Something I noticed (or didn't notice) was lack of fighting outside of the control zone. I was surprised not to see spawn camping or attempts at it.

Because it was the last day, yesterday I made a couple of attempts of ambushing enemy trucks about ~300 m outside the control zone using the IED, though it proved tricky to get the timing right. Obviously would be easier with mines, but I hadn't unlocked those.

Before anyone jumps on me: This is not a pro-spawn camping post. I understand teams need bodies in the control zone. I guess I was just expecting a little more of this style of play, though maybe I just didn't catch it having played under 10 hours.

Did anyone else see these kinds of hijinks? If I'm being honest, I did find the tower defense "meta" a little boring, but as others have pointed out these gameplay patterns are likely to shift as more players level up. Me being an ass with an IED was just a silly attempt to play a different way.